Step 1: Get a bunch of ukulele players.
Step 2: Play some cover songs.
Step 3: Have a good time.

Voodoo Marmalade – who declare themselves to be, “the first Portuguese ukulele band to exist,” play a number of songs that would fit into any ukulele orchestra/ensemble (Ring of Fire, Hit Me Baby…). What marks them out as something a bit more interesting is the way they throw in more recondite choices such as Zeca Baleiro’s Boi de Haxixe (best known, to me atleast, for Por Onde Andará Stephen Fry and Rachid Taha’s Ya Rayah. What do you mean you’ve heard Barra Barra?